Do you embrace the matrix?
Not this one, but the IT Organizational Matrix, or org chart. The fact is, once networks get to a certain size, IT organizations begin to specialize and small kingdoms emerge. For example, endpoint management (aka Desktop) may be handled by one team, whereas the data center is handled by another (Server team). Vulnerability scanning may be handled by a dedicated team but identity management (Active Directory? RSA tokens?) is handled by another. At this level of organization, these teams tend to have their own support infrastructure.
However, InfoSec controls are not separable from IT. What this matrix at the organizational level becomes is a graph of security dependencies at the information level. John Lambert explains in this blog post.
For example, the vulnerability scanning systems may use a “super privileged account” that has admin rights on every host in the network to scan for weaknesses, but the scanners may be patched or backed up by the Server team with admin rights to them. And the scanner servers themselves are accessed with admin rights from a set of endpoints that are managed by the Desktop team.
This matrix arising from domain specialization creates a honeycomb of critical dependencies. Why is this a problem? Well because it enables lateral movement. Attackers who don’t know the map or org chart can only navigate the terrain as it exists. In this case, though, the defenders may manage from the network map like good little blue tin soldiers.
If this is your situation, it’s time to simplify. Successful defenders manage from the terrain, not the map.